Your brain needs to clean itself. Not because it's cluttered with inane thoughts or clogged by your filthy sense of humor, but because—like every other organ—it creates waste products. Now, scientists have worked out how it keeps itself clean.

The rest of your body has this thing called the lymphatic system: a series of tubes and vessels that filter out garbage and ship it out of the body. But your brain's a small, sealed unit when it comes to waste. "If you look at a body-wide map of the lymphatic system, you see a great big void in the brain," explained neuroscientist Jeffrey Iliff to Wired.

Research from the University of Rochester Medical Center, though, has now shown that—in mice, at least—the brain has its own flushing mechanism, a bit like a toilet. It quite literally pumps fluid along the outside of blood vessels to wash crap away.

To work that out, the team of researchers monitored fluid flow in the brain using radioactive tracers. They observed that mouse brains have extracellular space through which cerebrospinal fluid flows to wash waste away. The team also showed that mice brains without such space cleared waste—including amyloid proteins which are linked to Alzheimer's—70 percent more slowly than normal mice. The results are published in Science.

While the finding in itself is interesting, perhaps more exciting is what the future holds for this kind of research. In theory, it should be possible to amp up the amount of flushing the brain does—which could in turn help scientists purge the junk that contributes to diseases like Parkinson's and Alzheimer's. [Science via Wired]